Essential amino acids are

$\begin{array}{1 1}(a)\;\alpha\text{ amino acids which are needed for health and growth of human being and are synthesised by human body}\\(b)\;\alpha\text{ amino acids which are needed for health and growth of human being but are not synthesised by human body} \\(c)\;\alpha\text{ amino acids which are needed for health and growth of human being but are not synthesised by human body}\\(d)\;\alpha\text{ amino acids which are needed for health and growth of human being and are synthesised by human body}\end{array} $